1,442 research outputs found
The Timing of Visual Object Categorization
An object can be categorized at different levels of abstraction: as natural or man-made, animal or plant, bird or dog, or as a Northern Cardinal or Pyrrhuloxia. There has been growing interest in understanding how quickly categorizations at different levels are made and how the timing of those perceptual decisions changes with experience. We specifically contrast two perspectives on the timing of object categorization at different levels of abstraction. By one account, the relative timing implies a relative timing of stages of visual processing that are tied to particular levels of object categorization: Fast categorizations are fast because they precede other categorizations within the visual processing hierarchy. By another account, the relative timing reflects when perceptual features are available over time and the quality of perceptual evidence used to drive a perceptual decision process: Fast simply means fast, it does not mean first. Understanding the short-term and long-term temporal dynamics of object categorizations is key to developing computational models of visual object recognition. We briefly review a number of models of object categorization and outline how they explain the timing of visual object categorization at different levels of abstraction
CISPLATIN (C) AND ALIMTA (A) WITH PANITUMUMAB FOR ADVANCED NON-SQUAMOUS NON-SMALL CELL LUNG CANCER (NS-NSCLC): A PHASE I-DOSE FINDING STUDY.
Background
The treatment of NSCLC is rapidly changing since new drugs are becoming available. Recently, CA has become a standard for the first line treatment of NS-NSCLC.
Previous clinical studies have shown that anti-EGFR MoAb may be added to chemotherapy, but the identification of a molecular signature can predict their activity and better define their true role.
Aims
In absence of data about the MTD of Panitumumab (a MoAb targeting the EGFR, potentially active in NS-NSCLC) when associated to chemotherapy, we decided to assess the optimal dose of panitumumab in combination with CA. Moreover, in view of a future phase II study, all pts will be studied for the following molecular characteristics: EGFR gene copy number (FISH); EGFR IHC; KRAS, BRAF, PI3KCA mutational status; ERCC1 and TS genes polymorphisms analysis. A particular attention will be paid to their possible correlation with outcome.
Materials and methods
Eligible patients must have: histological diagnosis of previously untreated, Stage IIIb or IV, NS-NSCLC, EGFR + (FISH).
A minimum of 6 to a maximum of 18 patients have to be treated with panitumumab at escalating doses (i.e. the first 3 patients at 5.5 mg/kg q3w, than in absence of dose limiting toxicities (DLT) the next 3 patients at 7.2 mg/kg q3w, than in absence of DLT toxicities the next 3 patients at 9 mg/kg q3w) in association with CDDP and at standard doses.
Activity and tolerability have been evaluated in terms of response rate and NCI-CTC v. 3.0.
Results
At the time of writing 8 patients have been screened for EGFR overexpression and 4 resulted eligible. None of the 3 patients treated with the first dose experienced a DLT, then the fourth patient is currently being treated with the second dose (7.2 mg/kg). One partial response and two disease stabilization have been
Cisplatin (C) and (A) with panitumumab for advanced non-squamous
non-small cell Lung cancer (NS-NSCLC): a phase I-Dose finding study.
ABSTRACT
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obtained, so far.
Conclusions
These very preliminary results have so far showed that panitumumab (at the present dose) can be safely associated with CA in NS-NSCLC patients. The study is currently on going
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Transition Probabilities Of Astrophysical Interest In The Niobium Ions Nb+ And Nb2+
Aims. We attempt to derive accurate transition probabilities for astrophysically interesting spectral lines of Nb II and Nb III and determine the niobium abundance in the Sun and metal-poor stars rich in neutron-capture elements. Methods. We used the time-resolved laser-induced fluorescence technique to measure radiative lifetimes in Nb II. Branching fractions were measured from spectra recorded using Fourier transform spectroscopy. The radiative lifetimes and the branching fractions were combined yielding transition probabilities. In addition, we calculated lifetimes and transition probablities in Nb II and Nb III using a relativistic Hartree-Fock method that includes core polarization. Abundances of the sun and five metal-poor stars were derived using synthetic spectra calculated with the MOOG code, including hyperfine broadening of the lines. Results. We present laboratory measurements of 17 radiative lifetimes in Nb II. By combining these lifetimes with branching fractions for lines depopulating the levels, we derive the transition probabilities of 107 Nb II lines from 4d(3)5p configuration in the wavelength region 2240-4700 angstrom. For the first time, we present theoretical transition probabilities of 76 Nb III transitions with wavelengths in the range 1430-3140 angstrom. The derived solar photospheric niobium abundance log epsilon(circle dot) = 1.44 +/- 0.06 is in agreement with the meteoritic value. The stellar Nb/Eu abundance ratio determined for five metal-poor stars confirms that the r-process is a dominant production method for the n-capture elements in these stars.Integrated Initiative of Infrastructure RII3-CT-2003-506350Swedish Research CouncilKnut and Alice Wallenberg FoundationBelgian FRS-FNRSFRIAUS National Science Foundation AST-0607708, AST-0908978Astronom
Selective Laser Melting of Ti6Al4V: Effects of Heat Accumulation Phenomena Due to Building Orientation
Titanium alloy Ti6Al4V is one of the most utilized alloys in the field of additive manufacturing due to the excellent combination of mechanical properties, density and good corrosion behavior. These characteristics make the use of this material particularly attractive for additively manufacturing components with complex geometry in sectors such as aeronautics and biomedical. Selective Laser Melting (SLM), by which a component is fabricated by selectively melting of stacked layers of powder using a laser beam, is the one of most promising additive manufacturing technologies for Ti6Al4V alloy. Although this technique offers numerous advantages, it has some critical issues related to the high thermal gradients, associated with the process, promoting the formation of a metastable martensitic microstructure resulting in high tensile strength but poor ductility of the produced parts. The formation of microstructural defects such as balling and porosity can occur together with the presence of residual stresses that may significantly affect the mechanical characteristics of the component. Specific process parameters and geometries can determine heat accumulation phenomena that result in a progressive decrease in thermal gradients between layers. These heat accumulation phenomena are influenced by the number of layers deposited, but also by the building orientation that, for a given geometry, determines a variation of the deposited surface for each layer. © 2022 The Author(s). Published by Trans Tech Publications Ltd, Switzerland
Evaluation of the burden of HPV-related hospitalizations as a useful tool to increase awareness: 2007–2017 data from the sicilian hospital discharge records
In light of the implementation of human papillomavirus (HPV) prevention strategies, epidemiological studies in different geographical areas are required in order to assess the impact of HPV-related diseases. The purpose of the present study was to describe the burden of HPV-related hospitalizations in Sicily. A retrospective observational study estimated 43,531 hospitalizations attributable to HPV from 2007 to 2017. During the observed period, there was a decrease for all HPV-related conditions with a higher reduction, among neoplasms, for cervical cancer (annual percent change (APC) = −9.9%, p < 0.001). The median age for cervical cancer was 45 years old, with an increasing value from 43 to 47 years (p < 0.001). The age classes with greater decreases in hospital admissions for invasive cancers were women aged 35 years or more (APC range from −5.5 to −9.86) and 25–34 years old (APC = −11.87, p < 0.001) for women with cervical carcinoma in situ. After ten years for vaccine introduction and sixteen years for cervical cancer screening availability, a relatively large decrease in hospital admissions for cervical cancer and other HPV-related diseases in Sicily was observed. Some clinical characteristics of hospitalization, such as increasing age, are suggestive clues for the impact of preventive strategies, but further research is needed to confirm this relationship
Ductility and linear energy density of Ti6Al4V parts produced with additive powder bed fusion technology
Hybrid metal forming processes involve the integration of commonly used sheet metal
forming processes, as bending, deep drawing and incremental forming, with additive
manufacturing processes as Powder Bed Fusion. In recent ybears, these integrations have been more developed for manufacturing sectors characterized by components with complex geometries in low numbers, as the aerospace sector. Hybrid additive manufacturing overcomes the typical limitations of additive manufacturing related to low productivity, metallurgical defects and low dimensional accuracy. In this perspective, a key aspect of hybrid processes is the production of parts characterized by high strength and ductility. In the present work, a study was carried out on
the influence of process parameters, such as laser power and scanning speed, on material ductility for Ti6Al4V alloy samples produced by Selective Laser Melting. In particular, the material strength and ductility were related to the process linear energy density (LED)
Simplified primary energy models for the selection of Electron Beam Melting over turning in the production of titanium alloys components
Over the last years two factors have deeply affected research in Manufacturing: the growing interest around Additive Manufacturing (AM) processes and the need to reduce the anthropogenic environmental impact. As result, a large papers concerning the environmental impact performance of AM compared to conventional processes have been published. Specifically, very complex models accounting for the impact of each life cycle stage of AMed components have been released. Results revealed that AM, at present, guarantees energy savings only within some domains, and the potential saving depends on several factors: product complexity, eco-properties of the material, energy intensity of the material deposition, light-weighting enabled by AM approaches and extent of the use phase. Above all, the result of the comparative analysis depends both on the considered factors and on the selected system boundaries. The already proposed models are very complex and many inventory data are needed, this could make them unapplicable at industrial level. In the presented paper, simplified models are proposed and the performances of these are quantified with varying the analyzed scenario (considered factors and selected system boundary). Results revealed that, for given scenarios, simplified models characterized by low computational effort, can provide reliable results. Guidelines for the implementation of different models with varying the system boundary are provided for the cumulative energy comparison of Electron Beam Melting and conventional turning for the production of titanium alloys components
\u201dBiweekly oxaliplatin combined with ral Capecitabine (OXXEL regimen) as first-line treatment of metastatic colorectal cancer patients. A Southern Italy Cooperative Oncology Group phase II study\u201d
Oxaliplatin 100 mg/m2 iv on day 1, and capecitabine 1,000 mg/m2 orally bid from day 1 (evening) to day 11 (morning) were administered every 2 weeks (OXXEL regimen) to 38 patients as first-line treatment for metastatic colorectal carcinoma. A total of 318 cycles were administered, with a median of 8 (range, 4-12) cycles per patient. Response rate (RR) was 45% (95% confidence interval (CI), 29%-62%), with 7 complete responses and 10 partial responses; furthermore, 12 patients showed a stable disease, so that a disease control was achieved in 29 (76%) patients. RR was greater among patients with performance status 0 (52%), without weight loss (52%), younger than 65 years (50%), and previously unexposed to adjuvant chemotherapy (48%), while no correlation was found with the actually delivered oxaliplatin dose intensity. Overall, haematological side effects were negligible, with no case of grade 4 toxicity, and only one patient suffering from an episode of grade 3 neutropenic fever. Severe anaemia occurred in 4 (11%) patients, and grade 3 neuropathy affected 9 (24%) patients. Median progression-free survival was 7.9 (95% CI, 6.2-9.6) months, and median overall survival has not been reached yet. In conclusion, the OXXEL regimen resulted safe and active, and it deserves further evaluation in metastatic colorectal cancer patients
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